The French Classical Algodon Mansion (suites from $400), in upscale Recoleta, became the city’s most exclusive boutique hotel when it opened in September. Inside the landmark building, expect discreet luxury rather than glitz: 10 ebony wood–floored suites have been decorated with a spare, masculine hand, and guests are given round-the-clock butler service. A block away, centennial magnolia trees shade a 1934 palace, part of the 165-room Palacio Duhau-Park Hyatt Buenos Aires (doubles from $495). Inside, crystal chandeliers and ornate plasterwork are offset by sleek Modernist furniture. Tucked among the early-20th-century town houses in the fashionable Palermo neighborhood, the restored Great Value Magnolia Hotel Boutique (doubles from $180) has an original stained-glass ceiling in the foyer and antique furnishings in the eight bedrooms. The fluted façade of the Great Value Moreno Hotel Buenos Aires (doubles from $148), located two blocks from the Casa Rosada, where Eva Perón gave her famous address, dates to the 1920’s—when Argentina embraced Art Deco. A concertina-gated elevator ferries guests up to the 39 ample rooms, fitted with furniture upholstered in sea greens or crimsons.